Vehicle

The engine lineup for ’70 was also revised with a new, thoroughly friendly 370-hp “LT-1” 350 joining the lineup and all the 427s departing in favor of two new 454-cubic-inch big-block V8s: a 390-hp “LS5” wearing a four-barrel carburetor and a tri-power-equipped “LS7” making a claimed 460 hp. However, the LS7 carried a $3,000 option price and there’s no record of any having been built. It would be a long while before Corvettes would be so powerful again.

With stricter emissions controls in force, the compression ratios on all Corvette engines dropped for 1971. The base 350 now plugged along with 270 hp, the LT-1 350 dropped to 330 hp and the detuned LS5 454 now made a mere 365 hp. Gone was the LS7 454 and in its place was an “LS6” 454 four-barrel V8 rated at 425 hp. Those are still heady numbers, but the diminution of Corvette performance would continue throughout the rest of the decade. Except for the power losses, the ’71 was essentially the same as the ’70.

The power drain would continue for 1972 and was exaggerated by a switch from SAE gross to SAE net power ratings. So the base 350 now carried a measly 200-hp rating, the LT1 made just 255 hp, and the sole big-block, an LS5 454, could only muster 270 hp. About 30 ’72 Corvettes were powered by a special “ZR-1” version of the LT-1 350 as part of a club-racing package.

A body-colored rubberized front bumper took up residence on the 1973 Corvette, replacing the chrome strip used previously. Furthermore, the side vents were now single, almost vertical, openings and radial tires were standard for the first time. Power dropped again, with the base 350 now rated at 190 hp and a new optional “L-82” 350 making 250 hp. The sole 454 was an “LS4” rated at 275 hp.

The ’73 Corvette’s rubber nose was paired with a matching wedge-shaped, body-colored tail on the 1974 Corvette as designers elegantly coped with new bumper regulations. There was some more jiggling of power ratings on the engines, but the big news was that this would be the last year for the big-block V8.

Read more about Corvettes at: http://www.edmunds.com/chevrolet/corvette/history.html